3D Computed Tomography Technique Research Articles

3D Ultrasound versus Computed Tomography for Tumor Volume Measurement Compared to Gross Pathology-A Pilot Study on an Animal Model.

The margin of the removed tumor in cancer surgery has an important influence on survival. Adjuvant treatments, prognostic complications, and financial costs are required when the pathologist observes a close/positive surgical margin. Ex vivo imaging of resected cancer tissue has been suggested for margin assessment, but traditional cross-sectional imaging is not optimal in a surgical setting. Instead, three-dimensional (3D) ultrasound is a portable, high-resolution, and low-cost method to use in the operation room. In this study, we aimed to investigate the accuracy of 3D ultrasound versus computed tomography (CT) to measure the tumor volume in an animal model compared to gross pathology assessment. The specimen was formalin fixated before systematic slicing. A slice-by-slice area measurement was performed to compare the accuracy of the 3D ultrasound and CT techniques. The tumor volume measured by pathological assessment was 980.2 mm3. The measured volume using CT was 890.4 ± 90 mm3, and the volume using 3D ultrasound was 924.2 ± 96 mm3. The correlation coefficient for CT was 0.91 and that for 3D ultrasound was 0.96. Three-dimensional ultrasound is a feasible and accurate modality to measure the tumor volume in an animal model. The accuracy of tumor delineation on CT depends on the soft tissue contrast.

Data-driven three-dimensional super-resolution imaging of a turbulent jet flame using a generative adversarial network.

Three-dimensional (3D) computed tomography (CT) is becoming a well-established tool for turbulent combustion diagnostics. However, the 3D CT technique suffers from contradictory demands of spatial resolution and domain size. This work therefore reports a data-driven 3D super-resolution approach to enhance the spatial resolution by two times along each spatial direction. The approach, named 3D super-resolution generative adversarial network (3D-SR-GAN), builds a generator and a discriminator network to learn the topographic information and infer high-resolution 3D turbulent flame structure with a given low-resolution counterpart. This work uses numerically simulated 3D turbulent jet flame structures as training data to update model parameters of the GAN network. Extensive performance evaluations are then conducted to show the superiority of the proposed 3D-SR-GAN network, compared with other direct interpolation methods. The results show that a convincing super-resolution (SR) operation with the overall error of ∼4% and the peak signal-to-noise ratio of 37 dB can be reached with an upscaling factor of 2, representing an eight times enhancement of the total voxel number. Moreover, the trained network can predict the SR structure of the jet flame with a different Reynolds number without retraining the network parameters.

Computed Tomography Cinematic Rendering in the Evaluation of Colonic Pathology: Technique and Clinical Applications.

Three-dimensional (3D) visualizations of computed tomography (CT) data have found use in the display of complex anatomy and pathology. A new method of 3D CT image creation known as cinematic rendering (CR) makes use of a global lighting model to produce photorealistic images. Cinematic rendering images contain high levels of detail with shadowing and depth that are not available from traditional 3D CT techniques. As yet, the role of CR in evaluating colonic pathology has not been investigated. However, given the breadth of pathologic processes that affect the colon, including inflammatory bowel disease, diverticulitis, neoplastic conditions, herniation, and gastrointestinal bleeding, we undertook a survey of recent cases at our institution to demonstrate colon pathology as visualized with CR. The following review discusses the role of 3D CT visualizations for colonic pathology with an emphasis on CR example images.

3D CT cinematic rendering of the spleen: Potential role in problem solving

Cinematic rendering (CR) is a new 3D visualization methodology for volumetric diagnostic imaging including computed tomography (CT) datasets composed of isotropic voxels. CR produces photorealistic images with enhanced detail relative to other 3D visualization methods and realistic shadowing. In this review, we provide a number of examples of splenic pathology visualized with CR including conditions affecting the splenic vasculature, neoplasms, and accessory spleens. These examples are compared to 2D CT and traditional 3D CT techniques and the potential advantages of CR are highlighted. CR displays textural changes in the splenic parenchyma to particular advantage, and a portion of this review will be devoted to examples of how textural features can help distinguish intrapancreatic accessory spleens from neuroendocrine tumors.

Dynamic Volume Computed Tomography Imaging of the Upper Airway in Obstructive Sleep Apnea.

To describe a dynamic three-dimensional (3D) computed tomography (CT) technique for the upper airway and compare the required radiation dose to that used for common clinical studies of a similar anatomical area, such as for subjects undergoing routine clinical facial CT. Dynamic upper-airway CT was performed on eight subjects with persistent obstructive sleep apnea, four of whom were undergoing magnetic resonance imaging and an additional four subjects who had a contraindication to magnetic resonance imaging. This Health Insurance Portability and Accountability Act-compliant study was approved by our institutional review board, and informed consent was obtained. The control subjects (n = 41) for comparison of radiation dose were obtained from a retrospective review of the clinical picture-archiving computer system to identify 10 age-matched patients per age-based control group undergoing facial CT. Dynamic 3D CT can be performed with an effective radiation dose of less than 0.38 mSv, a dose that is less than or comparable to that used for clinical facial CT. The resulting data- set is a uniquely complete, dynamic 3D volume of the upper airway through a full respiratory cycle that can be processed for clinical and modeling analyses. A dynamic 3D CT technique of the upper airway is described that can be performed with a clinically reasonable radiation dose and sets a benchmark for future use.

Three-dimensional computed tomography for determination of femoral anteversion in a cerebral palsy model.

Previous investigation has proven 3-dimensional (3D) computed tomography (CT) to be a poor method of assessing femoral anteversion in patients with cerebral palsy. However, new advancements in CT software yield the potential to improve upon those dated results. CT was performed on 9 femoral models with varying amounts of anteversion (20 to 60 degrees) and varying neck-shaft angles (120 to 160 degrees). Each model was scanned in 2 holding devices. One holder placed the femur in an ideal position relative to the gantry. The other placed the femur in flexion, adduction, and internal rotation simulating a common lower extremity posture in cerebral palsy. Femoral anteversion was measured on 3D reconstructions by 4 observers on 2 separate occasions. Interobserver and intraobserver reliability, accuracy, and the effect of increasing neck-shaft angle of the measurements were examined and compared with previously published data using the same models. Pearson correlation coefficients between first and second measurements by the same examiner were all above 0.96 regardless of positioning of the femur in the gantry. The correlation coefficients among all examiners were 0.97 regardless of positioning of the femur in the gantry. Accuracy in measurements was comparable using 3D CT techniques with mean differences between the normal and cerebral palsy-positioned models of <3.6 degrees (SD, 3.1 to 3.3 degrees). Accuracy of the study's 3D CT technique in measuring femoral anteversion in cerebral palsy-positioned femurs was significantly more accurate than that of 2D CT (P<0.0001). Recent improvements in processing software and 3D reconstruction have made assessment of femoral anteversion with 3D CT accurate through the studied range of anteversion and neck-shaft angles. Using this technique, high intraobserver and interobserver reliability in the determination of femoral anteversion can be expected regardless of neck-shaft angle or postural deformity. Level II.

Three-dimensional volume-rendering computed tomography for measuring humeral version

Humeral version is highly variable in human beings. Accurate assessment of humeral version may allow for more anatomic reconstruction at shoulder arthroplasty. Two-dimensional (2D) computed tomography (CT) has been used to measure humeral version but has limitations of poor interobserver reproducibility and strict dependence on arm positioning during image acquisition. This study evaluated a new technique, 3-dimensional (3D) volume rendering, for measuring humeral version. Eight dried human humerus specimens were included in the study. Gold standard measurements of humeral version were obtained by use of metallic beads and fluoroscopy. The specimens were then scanned at CT in 2 different positions, 1 neutral to the table and 1 angled at 20 degrees . The image data sets were used to measure humeral version in each bone with both the standard 2D technique and the new 3D technique. Measurements were performed by 3 readers at 2 different time points. Readers were blinded to the gold standard results and each others' measurements. For all readers, 3D measurements averaged within 4.3 degrees of the gold standard. For 2 of the 3 readers, 3D measurements were more accurate than 2D measurements. For all 3 readers, intraobserver variability was better with the 3D technique. For all reader pairs, interobserver variability was better with the 3D technique. This study shows a 3D volume-rendering CT technique to measure humeral version accurately and consistently that is independent of patient positioning.

Development of an ultra-high-speed scanning neutron tomography system for high-quality and four-dimensional visualizations

A new neutron tomography imaging system was developed in order to realize high-quality three-dimensional (3D) and four-dimensional (4D) visualizations by fusing the high-frame-rate neutron radiography and computed tomography (CT) techniques. The fundamental idea is that the object is revolved with high rotating speed and the neutron radiography images are recorded with a high-speed video camera and an image intensifier, and then the consecutive images are processed by a 3D CT technique. The 4D dynamic images of the sand flow in the sandglasses could be visualized clearly. This new technique has also an advantage in that it can reduce radio-activation of the object materials remarkably.

Chronic unreduced dislocations of the glenohumeral joint: imaging strategy and pathologic correlation.

Although the evaluation of acute or recurrent dislocations of the glenohumeral joint (GHJ) using routine radiography, specialized views, arthrography, and computed tomography (CT) has been extensively studied, methods of evaluation and osseous pathology of chronic unreduced GHJ dislocations are not well documented. In order to define such methods and pathology, we studied nine patients with chronic (greater than 6 months) unreduced anterior, posterior, superior, or central dislocations as well as one patient with a chronic rotator cuff injury; and seven scapular specimens, six with matching humeral specimens, with osseous abnormalities similar to those in the patients. We examined 15 additional scapular specimens with evidence of subluxation secondary to chronic rotator cuff injury. Standard, reformatted, and three-dimensional (3D) CT techniques were used to evaluate both the patients and the specimens. Our results indicate that characteristic alterations occur in the scapula and humeral head that are far more extensive than the classic Hill-Sachs, Bankart, and trough lesions. Such alterations occur at sites of osseous contact between the malpositioned humerus and scapula and are modified owing to prolonged adjustments made by the patients in an attempt to increase GHJ motion. Although routine radiography and specialized views are of some value, standard and 3D CT provide a more accurate analysis of the location and extent of the bone abnormalities and, as such, should be employed, particularly in the evaluation of patients in whom surgery is being considered.